SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c7046733ff4ffd2b7a91b3be971062f2eed906dadff0414b5c2b233f1e5d128' 
  AND token = 'CT854JkqizNyJ3lYPtdZuC7/PDRoCBt/mUuugrAe5pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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