SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc5d4d99a01c9df1154fd0a39f3760e1876190b7389ecc465499cfa4ec562c25' 
  AND token = 'QsHzJVjazMeq0Y0ZuMq0vcu27JK+iwcyP0UBhuOOJBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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