SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bb6eb45fc147435ecfc8917f6cba14951577ee08b36eccc5e1099590f2fd8e6' 
  AND token = 'nijNizlpUs3RUr3RruByjDl4AORJCgmVeh+uqbylSpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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