SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c81932c56ad184d27441e7718b36a8032d77a532414d7c6d77a4c9c8071d26' 
  AND token = 'LuuspxlgcUtyz/P4wA3EWWNaQQdNlBcqeESw0CJ86iI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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