SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a395ed971a4b1f133f5eb749a47c30244b5c05406cfd1fdbde6cff7603c2383c' 
  AND token = 'DxPhRNwgGRcEhUdHmDP+Zpez53aTmZH2EKtvJLMU0dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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