SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12cc952c659fcf7d2108603aa2d89f1bc361d3a69071076a2e55c85c3afc7bde' 
  AND token = 'ic6Y2mAZaNFjhBk6JiRkqplSaNqEjGaRGpJ7Jx8qRug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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