SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d74894283a39795b9af48cf2e8ab8335beaca4b5fe0a6c51b0e8fcfee27a92' 
  AND token = 'NwloWS5TeRtMblztahkrgEZ/vByEhdidXo4/Sq/d0o4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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