SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9859be4282e8f9f8415407ff55267086404ab6163a888a181c61b91dd3dee5b' 
  AND token = 'N27BoG0cZvYhPTgOedUIYbtgZMjh12pjyHoCAwCouIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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