SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0c29610b38b24ab073a7319bd099dec5baeda1a8a84a4c99d26e66028f37cfa' 
  AND token = 'svtDhGz27CHIfxmnkStsaZ2id7QyUJvkMgzJx9TV1QA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}