SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '499a48155ea98509b8cf577cb9f97a127e88d51349cf83cc61533809d5936a7f' 
  AND token = 'V//NSRb6IA+KBbgfKWwNNLMcdVy9kdNv5ZKyjiUchCQ=' 
  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"
    }
  }
}