SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7306086ca5ec6c8d6b40957f98b24366e94b4aa7093d537ef13cc4d2949375f7' 
  AND token = 'CR5ZkZjGs9zP2SpSrgbKJMSrHCu+5mIZeG7XfxsuOIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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