SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1bd2d25120a14e0fbb11d8358613fe170cb3582e6a46ec6f2c556b230e9e8f' 
  AND token = 'CMyvVRFgOz+PR02gjy7GLoYHMENSxS6kriFF3eK98ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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