SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a555f973c27342d996e54fa869ab1900ef4ae140fd70ae7a1dc47a593bbc5da1' 
  AND token = 'QnDO1Q3bsEQqQumYsafbfOTAn2iu/YB0m15Gs8QczDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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