SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fb94010a6a9dde14422f41bc8c24875cc077ba59d501ce33435270b336efc52' 
  AND token = 'jZ8tKcSUZ4Mry/MpqzcOOZQPBnBdNVqDI3hEHwE7H3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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