SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f80d087956f55dfb49f8164a2018c78f4cb7d5950c718c0ee23eb98c2a6f3409' 
  AND token = 'KW4/b7hqkQCI4808+u/O0Q+6vm05eKFuh3JtHVnwwbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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