SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d2676247fa2515d140c218591b84079bc42c6ee2831394f3e89d8dcfed2b912' 
  AND token = 'l8mYhcq0cVAZbXlIAKl3eE2MkIqM8EJb5TACqp7X790=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00098

JSON explain

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