SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba94550837e0756e8984500000fb873b3393c7ce69af4d1bee0099613b937ab' 
  AND token = 'zcstSEBhqnA+bocm/tuK/of4Ss9XezCfhxxNxw5KWEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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