SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '320c10c505d588b21c9aca8a9d8f613b201d90f7aeb909693586a25850d9b080' 
  AND token = 'qfSKb77pqilhUVSMN5IktJpdFGfhPGdpLwUeryXYssw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00082

JSON explain

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