SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46b04f08f68e8bccd68228c5886a0fefbfb442d56946162d00674b1e90b818a7' 
  AND token = 'mPL8VbDROgqhqxYXmH0hiN5SfKZ9HCLMXne77cWRCSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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