SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fabe539d353fd67ff8d4e89e0d4198e743ddc24fe66ed6efff14fdbfa21d12b' 
  AND token = 'HRBuDMPA2LVSCfmYpgYF1qpxSyuGPmKjQLrk0hPtf94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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