SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34f5a2d67d0162ec4925386926161f7081e5b22e8316d2d65137c9d06de91faf' 
  AND token = 'qK4vo/EiR02hv8QI9N5xA8qz8rpzsvHg/Hj6o+zV1Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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