SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c105e488f7d87d630070f893fdde0495e3b1632f70640c044ae7710c455df4ab' 
  AND token = 'hAZQauEF+98TzIcnKTczUnneL7ajwDddlVhUZrE5mqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}