SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22dd8829432e7678618438b2d730240b42b210e82f5e40672ae6fe7828060db9' 
  AND token = 'rUsChZ+qWFUPBZESESPNBlmVKkn3hLtpqTVlAWMTqIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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