SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd26991920b503bdb447467baf633d6bbe37f422729fc6855568e081e24e40e0' 
  AND token = 'VAl4axLqfEiVQaTx55Own0KeSZhGrHmN8slnixyQ7qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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