SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ebc77e7e837bdd4d91012e807ba0425781f85d0c420fe40fe7e5427fb4aaef0' 
  AND token = 'KVheQpIALK4ZLUoamQYB4L8NzW/m6U9W6axgbFtuSTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}