SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2442c9aaaffd372125d6429dc8fa382372e4593317c8845d646dd6cbd137f236' 
  AND token = 'yd9Al3qgmu/VGJr/XyZwn56qWIn/wHXwPWig9rBfanM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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