SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87564570025c8b0070aa18acf0c9f2adf85ae7492d1d02a63a2872d6e0ebad63' 
  AND token = '7J7mHaPCNpXGdBu6kGJ+943FH+UWzPO4D85pz5mLPYU=' 
  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"
    }
  }
}