SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '306aeb873beb76493b6b35e090ea3861db27213f7f8c21173e2ac4422bb029ca' 
  AND token = 'BGkgrUPwAK4ffqOf+C9aRNPOH8ZFH5O/0UjRmNuV9nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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