SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82009837eadb708484809fd120c7b3b6b3f1906b17c666ae6adddd5bcfaa8cbd' 
  AND token = 'SS/GJhCkZVyxOxa3/jler4F4yKgVF1nGhO46ARMMGDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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