SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9975d8601b857aaefcc97799e790d0695a71220cf4179ad87310135d1c90dad6' 
  AND token = 'X0nfBOJfgigu1TtDO8q5INKYUGXZ8Q3TNoGn3qcog7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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