SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1442882d8dd3d0428df886e19bf132913bc22863edcc3aad4a7813a17e76f2b8' 
  AND token = 'v5OhVtRJWetxgWxDMnkZIbrEp8ov5iK9B6LTlmEwsio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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