SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1431e8b5206803cfbcc2abe9bc47a34f575fdce69c67c1617d662b846603ba0' 
  AND token = 'eUDjtrzmSTpxvz3qOsB0oKj3Kz9anZ2vdFKR9vlv/8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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