SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fdefde85abfabc475243719ab1f79c65528d8adac4905461274d1f1e743beae' 
  AND token = 'xOlUqYjjw+h6ApN0u6/0ajnUaVw7/dniVqWZ1oFyqT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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