SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2c6096e07fa258a85af56b51c4ce9a17fed02c40b7518ac717fd65ecbafdfff' 
  AND token = 'a/HeEw/ArEwBisZWgXIhOxsB3lPjhnVA9UxI+2YEQLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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