SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b029dffab19245a0187ad8bbdb229843f6d96d6a8850f257136b088af4efa969' 
  AND token = 'y01ZkaXN5bZIch9YrT0khYN0ZCeek4nQOMARPZ/ofZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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