SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cfec7f4b9259cc7a7c733285f2faf0fc2919c18702ad01e427f2d5bb5975b35' 
  AND token = 'f2rMUaSjZnyKXJlerBSb3x2wiV4ICqvacpnL6oycMjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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