SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ec57a2e57664a298c6d92caa9d487051ca9e329d9e97c0e4474356535afc7f4' 
  AND token = 'bBsCTgr7tK7xWSdAS6GQYbRokQsjYIDvGPXq+AkRDnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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