SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6082b82ad5cc7864fc240d8493e372825349ac66cf11fa0dd371bc25ba8394a6' 
  AND token = '6qKAM6hMy+4Pl6SYJKGgi3FhSiWycRJSdZB41PvDZWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}