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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6dc9175e95515de9c8d641b7d8c884cea2ed5e4238614ae7315dab763efb3e' 
  AND token = 'HJW9WSHZp7SCmVHi98ih8pHzbME+SvR7mmmICEfO6GQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}