SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48487d9917bb1fe3e54b95437da3e6780ee2d01c9468327b8cc01e51ddb335af' 
  AND token = 'j39OjTW7lV9muLebMBSbi3ENojtQd+czhhOONXmnDn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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