SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9288e67a9aa34c89f262fbf4a03aca3e89ac5229c8db314178fa68567cb93a8' 
  AND token = 'jQDLzdwVRN0rHUCSr+rY2LulpLSbeYgNTn/DwZdIRgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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