SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22355f4bc2f12c5816fb968934bf0a27e59654e88203ebf8f997bbdfb99042af' 
  AND token = '3XXbDOpgQnL9vPS4AV1XBB3uynnV1nGUzCaUPq44Luo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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