SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e33ea7ae4a21af41c2926724ebc8038663293b26e03a7dcfa2bfc959a9443d4' 
  AND token = 'ZzihayvaQ5LAn4IDO+/BYH8lWtvtIONv+kp4jUf4gq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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