SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b16cd706096bd2d7fcfd0ecbfa7dc897b5dade04cb8551d2646b6cfda111a75' 
  AND token = 'GTJVpAqQxD47PnEyfByaCFvwA+84IRG54Lq4mNls0pw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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