SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a041c028aa876ddd5fc38549aaaca13f3b8a0e27cbefbb5f8247272035c652e' 
  AND token = '4DUNr+lqPKOTEBA8UECfmPXn6BwF3EVuemrFmZC7thE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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