SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07e36aaa5ff0e99056878d04cc6188812ecd203590de3237be9cf730ba667442' 
  AND token = 'gXDX/etSPhhRMmkBifCwwJtwqEJaTWdsqC6QG3aShiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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