SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2a5e8b7823ba0f937cf1cf9b6553ac111d7cbd91954860a4a66222d6e4dc98b' 
  AND token = 'BhnQduQkJ+YXezCHqDQu786whlwAjbcI9j7GDs5n7iE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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