SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ee95a29a3ebe7210ca545a3dd0ba824905e906ef63ea2dba45a3dd71479adbd' 
  AND token = 'Oq/FphGGEaw+rVy6e2kzWzIW4Nb+W27zbE6h1wg5hdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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