SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7263fdb2beae3a80f5df0799adffafdd41a3644196dc862975f16ed557d81ada' 
  AND token = 'hkDmYaLhiEs/5xEnVLrwLplnHHQFxKg4/04IfEgQkXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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