SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7a935d7ceef4da679a4f6b25e889da3ac9dc5bb19202049a439bddb06ab544' 
  AND token = 'UCGgXvZJdHwX8pgRl8vCkKCQOboXsilhUdAPSEjOAag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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