SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9486004f1113e0d10723bd8dfcc4bf0fb5da7e618983b43e2bf1b22182c2988e' 
  AND token = 'nC8OOh20PlqEFnDHcegVwTisXagsQe4yfhlVcraqa/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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