SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '161403bddea70ddf1c009bc0e129a2e360d2756975dabe285a7d8ea9fed5b2de' 
  AND token = 'bOll6DM0t85uTJqGVJU8p9/NXY6EWCUdriTpv7CWesI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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