SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd30207220522688cee32a3899861de04b10d03ba28409e8d363dbdadb83ee8b' 
  AND token = 'A+cAgzWcCeAvVah3AWvib95aJfiDlg3yLmNlOLfz+CE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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