SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa71e098f576ce373fcd6ec81fc51fa27f7b5556d96c221edee4b71697cc1d08' 
  AND token = '/m5NFg+kSBQsNV8qm0lGKuCUUDJ0BthXbsXoemfWzGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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