SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4c9458fd3e03966488779ea9ac5f85a44bb4f6ceeb4d265aef90824082dcda9' 
  AND token = '4Sffevf7+CWodfONwqxc3FWLVzxTFccqfbbEr6Gersg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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