SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb871307577284eefaaed08e24fa1014f3086692031266e6242bf60a7bf5be7' 
  AND token = 'yNkiNaTTwohRNizFi7s2pO0YltCt6aGCx+59U4a6XJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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