SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575c34691192b3c9c561d7cc8a850138de0ff74efb896496396697152f02210f' 
  AND token = 'FBnvESeBtRTnYd3PMUS2SSV5O2s2gfTaJxe7Svun1PI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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