SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13ff83ff54d5458fdab98b15693b945e73656a9eb45fab79120d6ea4a4f1bc1e' 
  AND token = 'j99aJxWhzEKffsfoJmigq/jLk+x1eGl3inoYIF5tBKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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