SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '323dfb55de5b11176324f99ff9a0aaeadd79818262848228ded38e3045923665' 
  AND token = 'ovs7ghUyUKYNKtGCQjTPHWRB5qUg3IlQRr6Q+qRs5LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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