SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '642d9519a20b1bf38b81a17a9f27fa3dc72fe37a2573a6bf8916773530dacfd4' 
  AND token = 'iha3evKbJrQ8fwegP9CrvDPqLNAuhuVJURBT0flaMzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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