SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c17969d323badf699416255d9aa1074ba5af54e42ef3347022fe50f9f27bdae' 
  AND token = 'HdiOoI17gavbXExV95SNbkwld/bd9DblHikANdDTP3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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