SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20146ad296743fda4a56af74766329aee0e39de8b367aec528df0dc7659ba2e4' 
  AND token = 'ZJb5SdUIgQaMY96oPcAa2rnE20vY02la9vWhKLGshXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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