SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02b50ba663b9916c862723ad7bb24cea2f852e051fc36281f102f2739bd7f0d1' 
  AND token = 'yCuMqZ8TbVmQ4EfQD1tYfPE7NCDyUKrhy48P/sUNbRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}