SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '554841c231602655a0ec26347a11c72b8f094c860d3c70ece90008d09703c701' 
  AND token = '1Sh/BtW6yCYhoB1Mb4QSHpN1ez1rQmL4GE0ShIyVci8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}