SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '293c52cd02e4fdc4d1175c023568462dee5b7c8b2abf19eaf65d4d77bb37055c' 
  AND token = 'pdlZAYTV3193UTPjM4LuntgHyGfhyu/haZBHhBHh4BM=' 
  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"
    }
  }
}