SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41c8052e247ade56925b4ff799f3f399d2f9b7a5194f3adb7d6b17b5ed1e261a' 
  AND token = 'e7I28NngBqmu1ZybgRccVedF1BPNNZtNahIY08AIsYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}