SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc86ce24572c188a1b9e73577ccdb32616032022fbb3aa9c4950ffe546a85adf' 
  AND token = '2I2weTvWCfyx/KK3Okrx/VsvqkH8vLUVheoGW+R6b1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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