SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9720e2194c63b0039a349c1c1f593225b5da58cc82c11953ff0186d67e5a42a7' 
  AND token = 'YDK9VihPEWEtixFqdf0R3TnSqKzULABGZYDkDHlGVx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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