Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3afdfe427e65bd078635f6b392ca619948e91e949c1b981c3722491d38d8f325' 
  AND token = '6SRtl1eIK6ZTgdDmTh7gSTqWSv9DKnxQ2aFawS1MS0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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