SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '5b4d63c04066188cdd9b53c3ff51cf56bc6f2bd1a40559a633a781f306515ea6' 
  AND token = '0EXpjCAKQkYFuVuEWtp1FxxpTYqBiQ9LfqvQcKu0fAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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