SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27517c782de49d80118d7722e6f2f4751ff6289aee311ef8b94084f756843e5c' 
  AND token = 'dbZPqBkvuD+HNpcgRXY5eknzu5s9OUiQKCMy3p3Ichw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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