SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddb4b912dfa95d53382326bb9d9030eb0e7efec5142890d2da23efb155e5816d' 
  AND token = '9eMRIvg0Y0Im1AqUwJgMxQwENiSpTh+q9xclubOEYi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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