SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c10e9bcc0b7ad1f49d1a7f1f8fd0c5c61436acf583dab2798e71345e1c2b2c6' 
  AND token = 'BcGCutKxyLhB0WUpwZnnZf0XUMUFMq5XDqPMqNbsVXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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