SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6baa151f392d583fa2ba41b199b22c9c65a3a4ba79878fc6d14b75efac951be3' 
  AND token = 'Z7vv0qItmgBW2mjZUPOWO8u713zUHFhx5bqZQCUH7dY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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