SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c5335593b374e88d6b8db1ec09682def615f09ffe168f2c935fabf3af641186' 
  AND token = 'lDHkcwaiCUwEBzxG9Njn8rmNmGO94CBZqJ27XUzxkrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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