SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a7abbe7df1035ceb646a044929cfed6828116b046b04185e22de09d7fdd33e3' 
  AND token = 'cUkSrPoMwIpLCzkRiB00kT8wcqI4mPP6wv7tQbeaaI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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