SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05e15574b6b2626373fdd1335d2a32c954f094ce9a506ba42e24932bf24e4f29' 
  AND token = 'd34bVSqOj+ZuQB87svxlvJ/emYBOQEk9W4CpoGmBDpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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