SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc270b7659f8241a110ccb367cebbc18df6b466d5ba20c8a89999e87247b17b' 
  AND token = 'ToIn76mRsFGKKTmPE3nJ47UCqq13iPPYl3oSw7RQYno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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