SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e35a8371e3cd8604a1f0b1ca8b4cf8e9c4b4ef812612008ec7eb1b8840d2b201' 
  AND token = '4YIbOL/ouekPL1VIHDQZbO8e7TThPlbxA7FwlQMUXVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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