SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d14cff91002c9f46391abf9862d884511ca0ee4b17ab575f8eecd9949550269' 
  AND token = '4K5v5mv4CYAE9l0odYfmoX6G1YsAgsVK2ePVcyIcYRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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