SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5536cfa0fbf0eeca7b27e8fba48053c96dfc2f1f84b83fd2a6f6fcf4a4bccfb' 
  AND token = '9zrQuKR6fvO+iScx0uhx/7WYiYcMp8PxZARQTy9U0fM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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