SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a941b1df1b8a9fb1f0df08e4f1e7dd0c2719ed3c1152b83dbb4cdbef6ad3b815' 
  AND token = 'PxO0bS2xYqBs7yE+RaMcGhkKqzvvCwUTSlsn7+hbWqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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