SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '149305d0ca81ee0d8e2867e5957f7883bfb5a326a14eaaf1d5634e640ec5b765' 
  AND token = 'Ad90FUaOwaD5vPIaQRndS/JlVcqIfmXmz7SkeVrBokA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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