SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '630d72fa62322db0a2401fa61b801481ba25effea8a2d321507fd96853897976' 
  AND token = '6jehy9E+OzMTp+MjPguj06/hCbmHqgVGzOEKoAEAqJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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