SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6cffa583618a08efba1578857869cb6919070abf10e1a195de7add8e7f70fe9' 
  AND token = 'wxzGayLedlyGpfcSgrmiKEXA9C+U0uQGWhx06f89EUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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