SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25a720233c981ca37f944a33db5ced3f5deb54b3788f591a9bc7bbec8c3d1247' 
  AND token = 'cPWHNxam233JnXsqkyg5YYl+HeMZSrPORqfB0yA9+VI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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