SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9e7cf4d37ba94d024db0257f14fd40ac28cd77b1c470fc0acb03c40754e70f9' 
  AND token = 'SaXWNvCxtwW5nS99VRR+xajNkaM1obGcthgSVfMPqaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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