SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2adeb6ace762636fbd7de5f36cd8c1d36a9a2f253f8aae0e7cd5f12d99e2f47b' 
  AND token = 'OaJA1/RlXrHBSC4Jq1QA0GzzjtvpqIrUb3hEhNFEhFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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