SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a379e3520d35aeb6cbf799e0bd48f648ad809b7c423567b210e3e90fabfb09' 
  AND token = 'muFF2ZC5SR20+pCxv1w8Jlk+7kxlFuSIU8B1jTnSLVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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