SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf1cde41195150c666480f1917bfc95f2fb1fc7c17ff20588a3c53cd0824d610' 
  AND token = 'AdSkNlGuA4yEztycOvcpEjjVJUBlWmS+t44q5N+MTn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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