SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6bf1e95b473092f1bee689b2ae3e50814917a7a8a001ff054412c47e47e48c8' 
  AND token = 'XxnePdzfwphQ6RIywiTGHAPVhuiUnyUZMGXlod9Z7vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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