SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7a705809a9866059205b28bba841920e1f62dd0dcd06a25946ba814e942438af' 
  AND token = 'DS6EiNLFlvhVydKQrGz0FXQRTO59cElHXQVIx3kTbt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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