SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'abdde5471348af49c16ad194625245972256e7330de77a77977b7c3d8085c1b8' 
  AND token = 'JxBuQGJQOEwMk1wI9O25Vr4Z4+/fR0R5ugwmlt1HMBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}