SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d54de8311472728992fd090b02b3042e1bb1b9c9503c017029864376c2330dd' 
  AND token = 'ODD0u91Fy7+h4bzFcbd/HcvI9fbSfBUtN/qiZ+JiPCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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