SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d4bfb60255dfb71dfe7d4fa51fb3c59c84676cd4952626939bc1d55d42b527f' 
  AND token = 'xykBeU9u67gUjwmc84zhJtfvnKhLmvV+kt0OQgZ/3R0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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