SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9f676afae630b7bc58d26f407d911a56fae665b8d162c3815e422055d985338' 
  AND token = 't3a26omwie8q6H9AQumKJvYJP/1cyb4T8Zw4hcMFNdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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