SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4ebfd3e8de8a05eb236e3c8cd830f36db47f9728bbd58071b493925624a2ce5' 
  AND token = 'oDya0r92KJzFjW6zCwL0xaF3lx0k4l70hDtzEaKVupA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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