SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e7623ea3756c77a7a2da23eb79b6360553202e694bd0432d839b88e0a40992d' 
  AND token = 'fd6FplfuY0VncUMFVfbcG5fUp0cSMwheHl+PqTdMqLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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