SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a85c92bc9985acd8b86ef05ef5a20688ab94e32ec8e1aa3daaa26d728c7781d1' 
  AND token = '2AO7tEVF8o1qsM+GDGfA2deRfQyk54VUFQEWe0XJQmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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