SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98a67630e8bdded8a0d7c56f0b49eb7c1e7faacd1ac8fc30c6f3cfeb49477ebf' 
  AND token = 'mlxVv4qUe+3yEM3T5Cc/S7PRO+tyvBng6kiYr4xDHfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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