SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76f5dd4dcbc418098e3c6709754e59165bd42796f9e4aed21a94e73914561f94' 
  AND token = '0Z2m9CZqhGbfvfk1NyQWEnA3ShUuSMu2ABtD1FIhLnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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