SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5350756321e543c3b488ebb248370f79a1cc961bf4e8e62f2d1dfe15a6adf5d1' 
  AND token = '7W8wQB4TUUytw849oECBvaI+aq7pmIhKQJLW41g8nbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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