SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef2609de81e944316d7d90feba008a2b7b91fe4acf0be20dfbe4859b4d4c8a5' 
  AND token = 'aaT9LG3MdYwhkGRH+FFloNPGh8JNerYwMMDhlRkXjL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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