SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2960444a7019900e8e11389d8deddc27afd0ea7dcad85554c6b156f252a05c90' 
  AND token = 'YSgo+sPFGooQo6M3Gz6rxVrbG7wBoLhmXRU1SlaHzTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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