SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '401c7ad7d50739f7a6ac7d496daf4d9b5947fa6c64c7265b476bee334786d236' 
  AND token = 'dgZOlJ4frdjryUcCwFTG5KhbNXz2HnuxkuGLPYdacgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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