SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '377f5adbe66b74fcb2d9b79e5318c3ffc1154736795a5eb4fbd5d99eca262795' 
  AND token = 'DVnY5SvpAJ3sfVR+BrdZM00m4FFNyVJEhUY8QwZGUbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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