SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63eae6068667feeaf7462c89107fdf28bdd8ee574d968329878e7cffe132acbd' 
  AND token = 'QEnDf5jlcnEK/6dzP0xMWQLB/LuXTypMBAbAvk7H7QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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