SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4930f89cc42afeac769f61714512f6c87a6012b0849ebf85cbedfa01102b48c' 
  AND token = 'sOUsNXoW+m9Gz08qHUu4rJ4QgS+FnFHOfIOLcoTY1Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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