SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc692896c31ffb04d9d187e3d7130cd8a05317e5d0844f169f34d3d74867dde' 
  AND token = '52ihtoYMQsFBkLaG8dHLyyRU8SIk/BtsA29/vnQzLnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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