SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b73f3a8d0b38c3a696f049c04f91b3da44b51e40d4cc68bc4bf0a777947ddcbc' 
  AND token = 'qREA7qXUdqGtv5VvNRUq/Zo780r/XKbHmRpYZllgV/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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