SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f03d73da395cdd217056cabce9087169ac79131fafd2de569e7954ea14061712' 
  AND token = 'scDxF7Wu8qVa5aFggNWuhDBhLorFU49zxbbtvjq7hJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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