SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9add725f9ef422117cfec01dd7ed7932554c5b4126e996a9b9f50ba97e9dc7c4' 
  AND token = 'APHYf4ewGMfkQXK2Ohl4zTT337gdIe5TXt2IN9BjaZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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