SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15e25797bfc8fd3e58b0c506193bcc708ce777228bfc21520d8481c62ed2fdb3' 
  AND token = 'rJUCdXjegeH7AtAbpsRT6ny3O135HOZQAOkTpwgI+bU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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