SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5cea3293003b3245c1029fd2860a523cb9ac8d8c182e9408cad0e16f0cd8cee' 
  AND token = 'cGQqGgXKuaUVtkSgUJtlfw+Bj0Za8Tnr5I6T/DnkPJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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