SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9dfe7f8e973f6c0b2a499f73841e4222d98648a22255e66dc180f9752610cbd' 
  AND token = 'FaqGmhhEbMgD/mGFvEYwqzfBz2fcv31qw7pQrUomJxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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