SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6109fb07145cd8b3934b7a47e44074098bafb50e34b95802711cb69d92e9fcdf' 
  AND token = 'NUaWzHuAustIXCPgJ0waF5KgEyODLEdKyCScdkmZ62I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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