SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae36905c3e87458151f23dd17b0bad76a7605c17a6259ee0ede21ebd1d5e2e1a' 
  AND token = '1WnWNDmwi/vsoV/qJNjDI3qXKk9tP53pxRe5CL69GfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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