SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2c9211814d9af1dd06388699e2a7aff1bfebbb643edb9014175cb27089d5beb' 
  AND token = '/5ctrxoaDtYdTP3g6JEsoB+cwioFpIWX+BrU6wc44sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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